System and/or method for error compensation in mechanical transmissions

Abstract

The system can include a set of joints, a controller, and a model engine; and can optionally include a support structure and an end effector. Joints can include: a motor, a transmission mechanism, an input sensor, and an output sensor. The system can enable articulation of the plurality of joints.

We claim: 
     
         1 . A system comprising:
 a set of joints mechanically connected to a base, each joint defining a respective rotational axis of the system, each joint comprising:
 an actuator comprising an actuator output component; 
 a mechanical transmission defining a drive end connected to the actuator output component and a driven end rotatable about the rotational axis of the joint; 
 a first encoder connected to the drive end and configured to sample a first rotational position of the drive end; and 
 a second encoder connected to the driven end and configured to sample a second rotational position of the driven end; and 
   a controller electrically connected to the actuator, first encoder, and second encoder of each joint, the controller comprising a backlash model for each joint of the system, wherein the controller is configured to control the actuator of each joint according to a set of control instructions, comprising:
 based on the first and second rotational positions at a first time, predicting a backlash error resulting at a second time with the respective backlash model for each joint; and 
 compensating for the predicted backlash error between the first and second times.